methæmoglobinæmia

Methaemoglobinæmia is a condition characterized by an abnormal level of methaemoglobin in the blood. Methaemoglobin is a type of haemoglobin that has been oxidized, rendering it unable to bind oxygen. Normally, about 1-2% of haemoglobin in the blood is in the methaemoglobin form, but in methaemoglobinæmia, this level increases to greater than 1%.

This condition can result from various causes, including the ingestion of certain medications or chemicals. Some drugs that can induce methaemoglobinæmia include aniline dyes, benzocaine, and local anaesthetics like prilocaine. Exposure to nitrates, certain lung conditions, and genetic disorders such as deficiency of cytochrome b5 reductase can also contribute to the development of methaemoglobinæmia.

Symptoms of methaemoglobinæmia can include shortness of breath, fatigue, headache, and dizziness. In severe cases, the condition can lead to cyanosis, a condition characterized by a bluish discoloration of the skin due to poor oxygenation. Diagnosis typically involves blood tests to determine the level of methaemoglobin in the blood.

Treatments for methaemoglobinæmia depend on its severity. Mild cases may require only supportive care, while more severe cases may require intravenous administration of methylene blue, a medication that helps convert methaemoglobin back to its normal form. In cases where the condition is caused by drug ingestion, treatment may involve forced diuresis or other methods to expel the offending agent from the body.